Check out College Football Data Warehouse. It has tons of statistics on all levels of football.
The I-AA page is here. UMass' page is here.
Warning! This site is a real work killer. Remember my post on new UMass Coach Bob Shoop ? We talked about Columbia's problems? Well, according to College Data Warehouse, if Columbia outscored its 2006 opponents 5,599-0, they would be even in points scored-points scored against!